Head rotator assembly for tape drive

ABSTRACT

A head rotator assembly ( 22 ) for positioning a head ( 20 ) of a tape drive ( 10 ) relative to a storage tape includes a head supporter ( 230 ) and a supporter mover assembly ( 232 ). The head supporter ( 230 ) is coupled to and supports the head ( 20 ). The supporter mover assembly ( 232 ) selectively rotates a portion of the head supporter ( 230 ) about an axis ( 241 ) to move the head ( 20 ) in an azimuth direction relative to the storage tape as the storage tape moves over the head ( 20 ). The head rotator assembly ( 22 ) further includes a controller ( 16 ) that controls movement of the supporter mover assembly ( 232 ) based at least partially on a positioning signal. The supporter mover assembly ( 232 ) can include a first actuator ( 234 A) and a first lever ( 236 A). The first actuator ( 234 A) moves the first lever ( 236 A) to rotate the head supporter ( 230 ) so that the head ( 20 ) moves in the azimuth direction. The first actuator ( 234 A) can include a piezoelectric element. The first actuator ( 234 A) biases the first lever ( 236 A) to rotate at least a portion of the head supporter ( 230 ) to move the head in the azimuth direction.

RELATED APPLICATIONS

The present application is a continuation application and claims thebenefit under 35 U.S.C. 120 on co-pending U.S. patent application Ser.No. 14/065,272, filed on Oct. 28, 2013, which claims the benefit under35 U.S.C. 120 on U.S. patent application Ser. No. 13/249,627, filed onSep. 30, 2011, now U.S. Pat. No. 8,599,519. To the extent permitted, thecontents of U.S. patent application Ser. No. 13/249,627 and U.S. Pat.No. 8,599,519 are incorporated herein by reference.

BACKGROUND

Linear tape drive systems provide for high-density recording on multipletracks of a magnetic storage tape (the “tape”). In certain arrangements,parallel tracks extend along a longitudinal direction of the tape.During recording or playback, the read/write elements of the head shouldbe aligned with the desired track as the tape moves in a longitudinaldirection across the head. Closed loop positioners are often used intape systems having higher track densities. In high-density tapesystems, the tape may wander in the lateral direction (perpendicular tothe longitudinal direction) as it moves in the longitudinal directionacross the head, which can result in a positioning error or offsetbetween the head and a center line of the desired track, also known astrack misregistration (TMR). This type of off-track condition can becaused by a number of factors including tape dimensional stability (TDS)and/or dynamic tape skew. TDS is normally caused by changes in theoperational temperature and/or relative humidity within the tape drive,which can cause changes the width of the tape. The ranges of temperatureand humidity in the tape drive are fairly broad, i.e. temperatures ofapproximately 50-104° F., and relative humidity of approximately 10-80%.Thus, the dimensions of the tape changes as temperature and/or humidityvary within these ranges.

Tape cartridges for high-density tape drives are typically preformattedwith information often called servo information, which is used tomaintain the correct lateral position of the tape with respect to thehead. Servo information provides the system with feedback to determinethe continuous position of the tape relative to the head. Analysis ofthe servo signals allows for a determination of an offset and thedistance of the offset between the track and the head. Based on theinformation, the head is moved by a positioner in the lateral directionto the center line of the track so that write/read operations can occurproperly.

Linear Tape Open (“LTO”) is a computer storage magnetic tape format thatemploys a servo-based, closed loop control mechanism. The LTO roadmapcalls for successive increases in capacity and speed, requiringincreased track densities. As track densities increase with each newgeneration of LTO tape cartridges, the ability to precisely control theread/write head relative to the magnetic tape becomes increasinglyimportant and more difficult, particularly due to phenomena such as tapedimensional stability and dynamic tape skew. These phenomena can causenot only lateral tape offset, but offset in other directions, such as anazimuth direction, particularly with such high track densities used intoday's tape cartridges.

SUMMARY

The present invention is directed toward a head rotator assembly forpositioning a head of a tape drive relative to a storage tape that movesover the head. In one embodiment, the head rotator assembly includes ahead supporter and a supporter mover assembly. The head supporter iscoupled to and supports the head. The supporter mover assemblyselectively rotates a portion of the head supporter about an axis tomove the head in an azimuth direction relative to the storage tape asthe storage tape moves over the head.

In accordance with one embodiment, the head rotator assembly furtherincludes a controller that receives a positioning signal from the head.The controller controls movement of the supporter mover assembly basedat least partially on the positioning signal. In one embodiment, thesupporter mover assembly includes a first actuator and a first lever. Inthis embodiment, the first actuator moves the first lever to rotate thehead supporter so that the head moves in the azimuth direction relativeto the storage tape. In one embodiment, the first actuator includes apiezoelectric element. In certain embodiments, the first actuator biasesthe first lever to rotate at least a portion of the head supporter sothat the head moves in the azimuth direction.

In one embodiment, the head supporter includes a supporter pivot. Inthis embodiment, the first lever rotates at least a portion of the headsupporter about the supporter pivot. The first actuator can impart anactuator bias force against the first lever in a first direction, andthe first lever imparts a lever bias force against the head supporter ina second direction that is different than the first direction. In oneembodiment, the first direction can be approximately perpendicular tothe second direction.

In another embodiment, the supporter mover assembly includes a secondactuator and a second lever. In this embodiment, the second actuatormoves the second lever to rotate the head supporter so that the headmoves in the azimuth direction. In certain embodiments, the secondactuator is on an opposite side of the head supporter from the firstactuator, and the second lever is on an opposite side of the headsupporter from the first lever.

In one embodiment, the head supporter can include a plurality of supportarms that flex to cause rotation of the portion of the head supporterabout the axis. The support arms can span approximately radially in adirection away from the axis. In one embodiment, the head rotatorassembly includes a support plate. In this embodiment, the headsupporter is at least partially fixedly secured to the support plate.

In addition to the aspects and embodiments described above, furtheraspects and embodiments will become apparent by reference to thedrawings and by study of the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with further advantages thereof, may best beunderstood by reference to the following description taken inconjunction with the accompanying drawings, taken in conjunction withthe accompanying description, in which similar reference charactersrefer to similar parts, and in which:

FIG. 1 is a perspective view of a tape cartridge and a partially cutawayview of a tape drive including one embodiment of a head assembly havingfeatures of the present invention;

FIG. 2A is a front perspective view of one embodiment of the headassembly including a head rotator assembly;

FIG. 2B is a front perspective view of a portion of the head assemblyillustrated in FIG. 2A including the head rotator assembly having a headsupporter;

FIG. 2C is a rear perspective view of a portion of the head assemblyillustrated in FIG. 2A including a portion of the head rotator assembly;

FIG. 2D is a front perspective view of a portion of the head assemblyillustrated in FIG. 2A including a portion of the head rotator assembly;

FIG. 3A is a perspective view of a portion of another embodiment of thehead assembly including a head rotator assembly;

FIG. 3B is a perspective view of a portion of the head rotator assemblyillustrated in FIG. 3A; and

FIG. 3C is a perspective view of the portion of the head rotatorassembly illustrated in FIG. 3B, shown in a first position and a secondposition.

DESCRIPTION

Embodiments of the present invention are described herein in the contextof a system and method for tape drive control. Those of ordinary skillin the art will realize that the following detailed description of thepresent invention is illustrative only and is not intended to be in anyway limiting. Other embodiments of the present invention will readilysuggest themselves to such skilled persons having the benefit of thisdisclosure. Reference will now be made in detail to implementations ofthe present invention as illustrated in the accompanying drawings. Thesame or similar reference indicators will be used throughout thedrawings and the following detailed description to refer to the same orlike parts.

In the interest of clarity, not all of the routine features of theimplementations described herein are shown and described. It will, ofcourse, be appreciated that in the development of any such actualimplementation, numerous implementation-specific decisions must be madein order to achieve the developer's specific goals, such as compliancewith application- and business-related constraints, and that thesespecific goals will vary from one implementation to another and from onedeveloper to another. Moreover, it will be appreciated that such adevelopment effort might be complex and time-consuming, but wouldnevertheless be a routine undertaking of engineering for those ofordinary skill in the art having the benefit of this disclosure.

FIG. 1 depicts a perspective view of one embodiment of a media drive 10(also sometimes referred to herein as a “drive”) constructed inaccordance with embodiments of the present invention, and a mediacartridge 12 (sometimes referred to herein as a “cartridge”), which isshown at least partially inserted within the drive 10 in FIG. 1. Thecartridge 12, such as an LTO tape cartridge as one non-exclusiveexample, is insertable at one end of the tape drive 10. The cartridge 12includes a storage tape (not shown) that stores data.

As one non-exclusive example, the drive 10 can be a tape drive. Thedesign of the drive 10 can vary. In some embodiments, the drive 10includes a housing 14, a controller 16 and a head assembly 18. The headassembly 18 includes a head 20 and a head rotator assembly 22. Thestorage tape bidirectionally moves across or over the head 20 in aback-and-forth direction (illustrated by bidirectional arrow 24) that issubstantially perpendicular to a lateral axis (illustrated by dashedline 26) of the head 20.

The specific design and location of the controller 16 can vary dependingupon the requirements of the drive 10 and/or the head rotator assembly22. In various embodiments, the controller 16 controls movement of thehead rotator assembly 22 and/or other types of head movers 228 (one headmover 228 is illustrated in FIG. 2A), such as voice coil motors, linearmotors, piezoelectric elements or other suitable head movers. The headrotator assembly 22 and/or the other head mover(s) 228 in turn move thehead 20 in one or more directions (i.e. rotation about one or more axesand/or linear movement along one or more axes) based at least in part ona positioning signal received from the head 20. This positioning signalis generated by the head 20 based on servo information located on thestorage tape.

In one embodiment, the head 20 transmits the positioning signal to thecontroller 16 to cause movement of the head rotator assembly 22 and/orthe other head movers. As a result, the head 20 is moved relative to thestorage tape, thereby attaining or maintaining the correct lateral,longitudinal, zenith and/or azimuth position of the head 20 with respectto the storage tape. This type of closed-loop system provides continuousfeedback to the controller 16 to determine and/or correct the positionof the head 20 relative to the storage tape.

FIG. 2A is a front perspective view of a portion of a tape drive 210including one embodiment of a head assembly 218. The head assembly 218includes a head 220 and a head rotator assembly 222. The head rotatorassembly 222 rotates or otherwise moves the head 220 in the azimuthdirection relative to the storage tape. The design of the head rotatorassembly 222 can vary to suit the design requirements of the drive 210.In the embodiment illustrated in FIG. 2A, the head rotator assembly 222includes a head supporter 230 and a supporter mover assembly 232. Thehead supporter 230 supports the head 220. The supporter mover assembly232 moves the head supporter 230. More specifically, the supporter moverassembly 232 causes rotation of the head supporter 230, which in turnrotates the head 220 in the azimuth direction relative to the storagetape, as described in greater detail below.

FIG. 2B is a front perspective view of a portion of the head assembly218 illustrated in FIG. 2A including the head 220 and the head rotatorassembly 222. In this embodiment, the head rotator assembly 222 includesthe head supporter 230 and the supporter mover assembly 232 which movesthe head supporter 230. In one embodiment, the supporter mover assembly232 includes one or more actuators and one or more levers. For example,in the embodiment illustrated in FIG. 2B, the supporter mover assembly232 includes a first actuator 234A, a second actuator 234B, a supportplate 235, a first lever 236A and a second lever 236B.

In one embodiment, the first actuator 234A and/or the second actuator234B can include one or more piezoelectric elements or a piezoelectricelement stack, for example. For example, in one embodiment, the firstactuator 234A and/or the second actuator 234B can include a 4 mmpiezoelectric stack. Alternatively, other size and/or types ofpiezoelectric elements can be used. Still alternatively, other suitabletypes of actuators can be utilized. In various embodiments, one portionof each of the first actuator 234A and the second actuator 234B isfixedly mounted to the support plate 235 so that another portion of eachcorresponding actuator 234A, 234B is movable. Upon receiving electricalvoltage, the movable portion of the first actuator 234A and the secondactuator 234B can exert a first actuator bias force (illustrated byarrow 238A) and/or a second actuator bias force (illustrated by arrow238B), upon the first lever 236A and/or the second lever 236B,respectively, as illustrated in FIG. 2B, resulting in movement of thelevers 236A, 236B.

The support plate 235 supports the head rotator assembly 222. In oneembodiment, the support plate 235 can be secured to another portion ofthe head assembly 218 such as to one or more of the head movers 228(illustrated in FIG. 2A), as one non-exclusive embodiment. In certainembodiments, the head supporter 230 of the head rotator assembly 222 canbe fixedly secured to the support plate 235 at a supporter pivot 239(illustrated in FIG. 2C) which is located substantially at or near asupporter pivot axis 241 (illustrated by dashed line in FIG. 2C) of thehead supporter 230. In one embodiment, the supporter pivot axis 241 islocated near the center of the head supporter 230. Alternatively, thesupporter pivot axis 241 can be located off-center.

In the embodiment illustrated in FIG. 2B, the first lever 236A includesa first actuator contact 240A and a first lever pivot 242A. The secondlever 236B includes a second actuator contact 240B and a second leverpivot 242B. The first actuator contact 240A contacts the first actuator234A, and the second actuator contact 240B contacts the second actuator234B. In one embodiment, the pivot levers 242A, 242B are each pivotallysecured to the support plate 235 in a manner known to those skilled inthe art, such as by a bearing and a pin forming a pivot construction, asone non-exclusive example. Alternatively, the one or more of the pivotlevers 242A, 242B can be pivotally secured to another suitable structurewithin the drive 10. In various embodiments, the levers 236A, 236B canbe formed from any suitably rigid material such as stainless steel,aluminum, etc., as non-exclusive examples. In one embodiment, the levers236A, 236B are somewhat L-shaped. However, the levers 236A, 236B canhave another suitable configuration.

Upon exertion or increase of the first actuator bias force 238A by thefirst actuator 234A against the first actuator contact 240A of the firstlever 236A, the first lever 236A pivots or rotates about the first leverpivot 242A in a clockwise direction (illustrated by rotational arrow244A) as viewed in FIG. 2B. Somewhat similarly, upon exertion orincrease of the second actuator bias force 238B by the second actuator234B against the second actuator contact 240B, the second lever 236Bpivots or rotates about the second lever pivot 242B in a clockwisedirection (illustrated by rotational arrow 244B) as viewed in FIG. 2B.

Additionally, in this embodiment, each lever 236A, 236B includes acorresponding supporter contact. More specifically, the first lever 236Aincludes a first supporter contact 246A, and the second lever 236Bincludes a second supporter contact 246B. Further, the head supporter230 includes a first lever contact 248A and a second lever contact 248B.The first supporter contact 246A contacts the first lever contact 248Aof the head supporter 230. The second supporter contact 246B contactsthe second lever contact 248B of the head supporter 230. Upon rotationof the levers 236A, 236B about their respective pivot levers 242A, 242B,the first supporter contact 246A exerts a first lever bias force(illustrated by arrow 250A) against the first lever contact 248A, andthe second supporter contact 246B exerts a second lever bias force(illustrated by arrow 250B) against the first lever contact 248B. Thesebias forces 250A, 250B result in movement of the head supporter 230 asdescribed herein.

In the embodiment illustrated in FIG. 2B, the combination of bias forces250A, 250B against the head supporter 230 causes rotation of the headsupporter 230, as described in greater detail below. This rotation ofthe head supporter 230 results in rotation of the head 220 in an azimuthdirection (illustrated by arrow 252) relative to a storage tape thatmoves over the head 220 during operation of the tape drive 10. It isrecognized that both bias forces 250A, 250B are not necessary to resultin rotation of the head 220 in an azimuth direction. However,embodiments that utilize two or more such bias forces 250A, 250B canresult in more even movement, better balance, increased accuracy and/orgreater responsiveness of the head rotator assembly 222.

In various embodiments, the first actuator bias force 238A between thefirst actuator 234A and the first lever 236A is in a first direction,and first lever bias force 250A between the first lever 236A and thehead supporter 230 is in a second direction that is different than thefirst direction. In one embodiment, the first actuator bias force 238Abetween the first actuator 234A and the first lever 236A is in a firstdirection, and first lever bias force 250A between the first lever 236Aand the head supporter 230 is in a second direction that isapproximately perpendicular to the first direction.

Conversely, if voltage to the actuators 234A, 234B is decreased, themovable portion of the first actuator 234A and the second actuator 234Bcan contract, thereby decreasing the first actuator bias force 238Aand/or the second actuator bias force 238B, upon the first lever 236Aand/or the second lever 236B, respectively. Upon decrease of the firstactuator bias force 238A by the first actuator 234A against the firstactuator contact 240A, the first lever 236A pivots or rotates about thefirst lever pivot 242A in a counterclockwise direction (opposite ofrotational arrow 244A). Somewhat similarly, upon decrease of the secondactuator bias force 238B by the second actuator 234B against the secondactuator contact 240B, the second lever 236B pivots or rotates about thesecond lever pivot 242B in a counterclockwise direction (opposite ofrotational arrow 244B). Upon such opposite rotation of the levers 236A,236B about their respective pivot levers 242A, 242B, the first leverbias force 250A of the first supporter contact 246A against the firstlever contact 248A decreases, and the second lever bias force 250B ofthe second supporter contact 246B against the first lever contact 248Blikewise decreases. The net result of these decreases in lever biasforces 250A, 250B results in rotation of the head supporter in anopposite direction from that illustrated in FIG. 2B, thereby causing thehead 220 to rotate in an azimuth direction opposite of that illustratedby rotational arrow 252.

In operation, in one embodiment, the first actuator 234A and/or thesecond actuator 234B are under closed loop servo control and canperiodically and/or continuously receive electrical voltage from thecontroller 16 (illustrated in FIG. 1). For example, at various sampletimes, i.e. one time per millisecond (or any other suitable increment oftime, or varying increments of time), the tape drive 10 can detect arequired adjustment in the azimuth angle of the head 220 relative to thestorage tape, and can send a control input (voltage) to the actuators234A, 234B to ultimately move the head 220 to a target azimuth angle.The range of movement of the head 220 can vary depending upon thegeometry of the actuators 234A, 234B, the levers 236A, 236B and the headsupporter 230, as well as the positioning and dimensions of othercomponents within the drive 10. In one non-exclusive embodiment,movement of the head supporter 230 by approximately 6 microns can resultin movement of the head 220 by approximately 4 arc minutes of rotation.

Altering the positioning of the various components described herein canresult in tuning of the head rotator assembly 222. As one non-exclusiveexample, the positioning of the pivot levers 242A, 242B relative to theactuator contacts 240A, 240B can alter the degree of rotation of thelevers 236A, 236B. Further, the dimensions of the levers 236A, 236B caninfluence the extent of the forces that are ultimately transferredand/or translated from the actuators 234A, 234B to the head supporter230, as recognized by those skilled in the art. The foregoing examplesare only representative of the changes in either or both of positioningand/or dimensions of various structures that comprise the head rotatorassembly 222 and/or other structures of the tape drive 10, and are notintended to be limiting in any way.

FIG. 2C is a rear perspective view of a portion of the head assembly 218illustrated in FIG. 2A including the head 220 and a portion of the headrotator assembly 222. In this embodiment, the supporter pivot 239, whichcan be attached to the support plate 235 (illustrated in FIG. 2B), isvisible. In one embodiment, the supporter pivot 239 of the headsupporter 230 is fixedly attached to the support plate 235, while theremainder of the head supporter 230 is unattached to the support plate235. This configuration allows for rotation of at least a portion of thehead supporter 230 about the supporter pivot axis 241 of the supporterpivot 239.

FIG. 2D is a front perspective view of a portion of the head assembly218 illustrated in FIG. 2A including a portion of the head rotatorassembly 222. In certain embodiments, the head supporter 230 includesone or more support arms 254 (10 support arms are illustrated in FIG.2D, although only 4 support arms are labeled) that span approximately orsubstantially radially away from the supporter pivot 239. In thisembodiment, upon exertion of the lever bias forces 250A, 250B on thehead supporter 230, the support arms can flex (shown by 10 unlabeledarrows) to allow rotation of at least a portion of the head supporter230 about the supporter pivot 239. The dimensions, i.e. thickness,length and width of the support arms 254 can be varied in order to tunethe extent of rotation of the head supporter 230.

In one embodiment, the head rotator assembly can include a sensorassembly 256 for measuring the extent of rotation and/or linear movementof a portion of the head supporter 230. The sensor assembly can bevaried, but in one embodiment, the sensor assembly 256 can include aLinear Hall Effect sensor 258 and a magnet 260 which cooperate toprovide information to the controller 16 (illustrated in FIG. 1) forclosed loop feedback. During movement of the head supporter 230, themagnet 260 and/or the Linear Hall Effect sensor 258 move relative to oneanother to provide input to the controller 16 on a periodic orcontinuous basis.

FIG. 3A is a perspective view of a portion of another embodiment of thehead assembly 318, including a head 320 and a head rotator assembly 322.In this embodiment, the head rotator assembly 322 operates in a somewhatsimilar manner as the embodiments previously described such that thehead rotator assembly 322 rotates or otherwise moves the head 320 in theazimuth direction relative to the storage tape. In the embodimentillustrated in FIG. 3A, the head rotator assembly 322 includes a headsupporter 330 and a supporter mover assembly 332. The head supporter 330supports the head 320. The supporter mover assembly 332 moves the headsupporter 330. More specifically, the supporter mover assembly 332causes rotation of the head supporter 330, which in turn rotates thehead 320 in the azimuth direction relative to the storage tape.

In this embodiment, however, the supporter mover assembly 332 has asomewhat different configuration than the supporter mover assembly 232(illustrated in FIG. 2A) previously described. More specifically, inthis embodiment, the supporter mover assembly 332 includes a firstactuator 334A, a first actuator support 362A, a first lever 336A, afirst clamp 364A and a first lever bearing surface 366A. It should beunderstood that although only one side of the head rotator assembly 322is being described herein for the sake of simplicity, in variousembodiments, an opposing side (not shown) of the head rotator assembly322 would also be present, which would include a second actuator, asecond actuator support, a second lever, a second clamp and a secondlever bearing surface. The components of the opposing side of the headrotator assembly 322 can be somewhat similarly positioned, albeitsubstantially symmetrical about a supporter pivot 339 of the headsupporter 330.

In the embodiment illustrated in FIG. 3A, the first actuator 334A ispartially fixedly secured to the first actuator support 362A. In oneembodiment, the first actuator can be a piezoelectric element or stackwhich expands and/or contracts based on the level of voltage applied tothe first actuator 334A. A portion of the first actuator remainsunsecured to the first actuator support 362A, and extends to contact thefirst lever 336A. In this embodiment, the first lever 336A is secured inplace with the first clamp 364A rather than with a pivot lever, aspreviously described. Thus, the first lever 336A does not pivot aboutthe pivot lever, but instead flexes upon a force being exerted by thefirst actuator 334A, as described in greater detail below. The firstlever 336A contacts the first lever bearing surface 366A, which issecured to one of the first lever 336A or the head supporter 330.

As an overview, the first actuator 334A receives voltage from thecontroller 16 (illustrated in FIG. 1), causing the first actuator toexert a force on the first lever 336A, thereby flexing the first lever336A. Flexing of the first lever 336A results in the first lever 336Aexerting a force on the first lever bearing surface 366A, causing thehead supporter 330 to rotate about the supporter pivot 339. Thisrotation of the head supporter 330 causes rotation of the head 320 inthe azimuth direction, as previously described herein. This embodimentis particularly effective when the first lever 336A and the second lever(not shown) are working simultaneously to more symmetrically rotate thehead supporter 330 to move the head 320 in the azimuth direction asrequired based on servo information received by the controller 16. Inthis embodiment, because the first lever 336A is not secured via a pivotlever, certain inefficiencies or errors due to clearance between a pinof the pivot and a bearing hole of the pivot lever can be reduced oravoided entirely.

FIG. 3B is a perspective view of the first lever 336A of the headrotator assembly 322 illustrated in FIG. 3A. In this embodiment, thefirst lever 336A includes an actuator contact 340, a supporter contact346, one or more clamp wings 368 (two clamp wings are shown in FIG. 3B),and one or more flex connectors 370 (two flex connectors are shown inFIG. 3B). The actuator contact 340 is a raised region of the first lever336A that contacts the first actuator 334A (illustrated in FIG. 3A). Thesupporter contact 346 contacts the lever bearing surface 366A(illustrated in FIG. 3A) of the head supporter 330 (illustrated in FIG.3A).

The clamp wings 368 can be fixedly held in position by the clamp 364A(illustrated in FIG. 3A) so that there is essentially a zero clearanceand very little, if any, movement of the clamp wings 368 during movementof the remainder of the first lever 336A. The flex connectors 370 areconnected to the clamp wings 368. The flex connectors 370 are flexibleunder a load by the first actuator 334A, thereby allowing the remainderof the first lever 336A to move while the clamp wings 368 remainsubstantially stationary. The flex connectors 370 can be constructed ofa different, more flexible material than the clamp wings 368.Alternatively, the flex connectors 370 can be constructed of the samematerial as the clamp wings 368, but can have smaller dimensions whichallow less restricted movement to allow the remainder of the first lever336A to flex and move under load by the first actuator 334A.

In accordance with the embodiment illustrated in FIG. 3B, an actuatorbias force imparted by the first actuator 334A (illustrated in FIG. 3A)in a first direction (represented by arrow 372) results in flexing ofthe flex connectors 370 and movement of the first lever 336A so that thesupporter contact 346 moves in a second direction (represented by arrow374) that is different than the first direction 372. In one embodiment,the first direction 372 is approximately perpendicular to the seconddirection 374.

FIG. 3C is a perspective view the first lever 336A of the head rotatorassembly 322 illustrated in FIG. 3A, shown in a first position 376 and asecond position 378 that is superimposed on the first position 376 toshow movement of the first lever 336A. In the first position 376, alesser force is being imparted by the first actuator 334A (illustratedin FIG. 3A) on the first lever 336A than when the first lever 336A isshown in the second position 378. Stated another way, an increased forceby the first actuator 334A on the first lever 336A biases the firstlever 336A from the first position 376 to the second position 378.Although the clamp wings 368 essentially do not move any significantamount, the remainder of the first lever 336A does move, which allowsthe first lever 336A to impose a lever bias force on the head supporter330 (illustrated in FIG. 3A) as required to rotate the head 320(illustrated in FIG. 3A) in the azimuth direction.

All of the following disclosed embodiments are used in conjunction withcontrol logic operative to control movement of the head rotator assemblyin the azimuth direction under closed loop servo control. A variety ofalgorithms can be used to move the head rotator assembly 22, andtherefore the head 20, in the azimuth direction in response to tapedimensional stability and/or dynamic tape skew of the storage tapedetected by monitoring servo signals.

While a number of exemplary aspects and embodiments have been discussedabove, those of skill in the art will recognize certain modifications,permutations, additions and sub-combinations thereof. It is thereforeintended that the following appended claims and claims hereafterintroduced are interpreted to include all such modifications,permutations, additions and sub-combinations as are within their truespirit and scope.

What is claimed is:
 1. A head rotator assembly for dynamicallycompensating for a tape skew of a storage tape that moves over a head ina tape drive, the head rotator assembly comprising: a head supporterthat is coupled to and supports the head; and a supporter mover assemblyincluding a first actuator that indirectly rotates a portion of the headsupporter about an axis to move the head in an azimuth directionrelative to the storage tape to dynamically compensate for the tape skewas the storage tape moves over the head.
 2. The head rotator assembly ofclaim 1 wherein the supporter mover assembly further includes a firstlever, the first actuator moving the first lever to rotate the portionof the head supporter so that the head moves in the azimuth directionrelative to the storage tape to dynamically compensate for the tapeskew.
 3. The head rotator assembly of claim 2 wherein the first actuatorexerts a force against the first lever to rotate the first lever about alever pivot in a first rotational direction, and wherein upon therotation of the first lever in the first rotational direction, the firstlever exerts a force against the head supporter to rotate the headsupporter about a supporter pivot in a second rotational direction thatis different than the first rotational direction.
 4. The head rotatorassembly of claim 2 wherein the first actuator exerts a force againstthe first lever to flex the first lever, and wherein upon the flexing ofthe first lever, the first lever exerts a force against the headsupporter to rotate the head supporter about a supporter pivot to movethe head in the azimuth direction relative to the storage tape todynamically compensate for the tape skew.
 5. The head rotator assemblyof claim 2 wherein the first actuator imparts an actuator bias forceagainst the first lever in a first direction, and the first leverimparts a lever bias force against the head supporter in a seconddirection that is different than the first direction.
 6. The headrotator assembly of claim 5 wherein the first direction is approximatelyperpendicular to the second direction.
 7. The head rotator assembly ofclaim 1 further comprising a controller that receives a positioningsignal from the head, the controller controlling movement of thesupporter mover assembly based at least partially on the positioningsignal.
 8. The head rotator assembly of claim 1 wherein the firstactuator includes a piezoelectric element.
 9. The head rotator assemblyof claim 1 wherein the supporter mover assembly further includes asecond actuator that indirectly rotates the portion of the headsupporter about the axis to move the head in the azimuth directionrelative to the storage tape to dynamically compensate for the tapeskew.
 10. The head rotator assembly of claim 9 wherein the supportermover assembly further includes a second lever, the second actuatormoving the second lever to rotate the portion of the head supporter sothat the head moves in the azimuth direction relative to the storagetape to dynamically compensate for the tape skew.
 11. The head rotatorassembly of claim 9 wherein the second actuator is on an opposite sideof the head supporter from the first actuator.
 12. The head rotatorassembly of claim 1 wherein the supporter mover assembly furthercomprises a support plate, and wherein the head supporter is at leastpartially fixedly secured to the support plate.
 13. A tape driveincluding a head and the head rotator assembly of claim 1 that supportsthe head.
 14. A method for positioning a head of a tape drive relativeto a storage tape that moves over the head, the method comprising thesteps of: supporting the head with a head supporter that is coupled tothe head; and dynamically compensating for a tape skew by indirectlyrotating a portion of the head supporter about an axis with a firstactuator to move the head in an azimuth direction relative to thestorage tape as the storage tape moves over the head.
 15. The method ofclaim 14 wherein the step of dynamically compensating includes the stepsof moving a first lever with the first actuator, and rotating theportion of the head supporter with the first lever to move the head inan azimuth direction relative to the storage tape as the storage tapemoves over the head.
 16. The method of claim 15 wherein the step ofmoving includes the step of imparting an actuator bias force with thefirst actuator against the first lever in a first direction, and whereinthe step of rotating includes the step of imparting a lever bias forcewith the first lever against the head supporter in a second directionthat is different than the first direction.
 17. The method of claim 14further comprising the steps of receiving a positioning signal from thehead with a controller, and controlling movement of the first actuatorwith the controller based at least partially on the positioning signal.18. The method of claim 14 further comprising the step of dynamicallycompensating for the tape skew by indirectly rotating a portion of thehead supporter about an axis with a second actuator to move the head inan azimuth direction relative to the storage tape as the storage tapemoves over the head.
 19. The method of claim 18 wherein the step ofdynamically compensating for the tape skew by indirectly rotating theportion of the head supporter about an axis with the second actuatorincludes the steps of (i) moving a second lever with the secondactuator, and (ii) rotating the portion of the head supporter with thesecond lever to move the head in an azimuth direction relative to thestorage tape as the storage tape moves over the head.
 20. The method ofclaim 14 further comprising the step of fixedly securing at least aportion of the head supporter to a support plate.